The field of this invention relates generally to an apparatus for selecting and indicating a specific color combined from the four standard primary colors of the four-color printing process which permits combining two or more shades of colors without the necessity of actually mixing liquid quantities of the colors.
Within printing, there is always a need to select colors. Colors are commonly used within printed documents such as advertisements and brochures. The selection of a particular color can be very important to not only make the document look attractive but also to be eye-catching. It is also important that a particular color may be required to blend with one or more other colors.
It is common that upon arriving at a particular color to use a screening wheel or disc. The basic construction of a screening wheel is transparent. Reproduced on the wheel are a plurality of windows with each window being of a particular percentage of screened tint of the particular color for that wheel. It is common for there to be a wheel for each primary color. Locating of the windows of the wheels in an overlapping arrangement visually blends the individual window colors to produce a particular color shade. Changing of the amount of tint in any one wheel, in other words changing of a window, will result in changing of the shade that is produced. Using of these color wheels will result in producing of an actual color without actually producing the colored ink itself. Therefore, a purchaser of printing can select the exact colors that will be produced within the printing operation without producing the actual liquid ink.
In the past, such wheels were not designed to be of the utmost convenience to the user. The wheels could be moved easily relative to each other, generally about a pivot post. However, the different tints that made up the produced color were not immediately perceivable but had to be determined by flipping individually from wheel to wheel. Also, to assist the user, it is normally preferable that the aligned windows of the individual discs are to be precisely overlapped. There has not been known any device usable in conjunction with these prior art wheels to precisely arrange these wheels in an exact overlapping arrangement.